A standard refrigeration or air conditioning system includes an evaporator or cooling unit, a compressor, a condenser, and an expansion valve. A refrigerant circulates through these component parts with the refrigerant being under high pressure and converted to a liquid stage in a condenser. A pressure reduction or expansion valve allows the liquid fluid to flow into the evaporator wherein the pressure is greatly reduced and the liquid refrigerant is converted to a vapor state. A compressor creates a vacuum on the discharge of the evaporator to draw the vaporized fluid therein and to pressurize the vapor prior to flowing into the condenser. The cycle is repeated for continued cooling.
Within the condenser, heat is given off to the surrounding environment by any convenient means, such as having air flowing therethrough. In the evaporator, heat is absorbed from the surrounding environment, again a typical method being to have air flowing therethrough to cool an enclosed area.
In any standard refrigeration or air conditioning system, the compressor utilizes the most energy. The energy requirements of the compressor are nearly directly proportional to the pressure differential between the output of the evaporator and the input of the condenser. The requirements of the entire system can be reduced by merely reducing this pressure differential across the compressor.
The present invention decreases this pressure differential and the corresponding energy requirements by combining a standard refrigerant or air conditioning system with a thermal energy system adapted to work in series with the compressor to assume some of the compressor work load, or to condense the fluid in the condenser at a temperature lower than ambient. This decreases the temperature drop and pressure differential across the compressor. In the second case, the particular refrigeration or air conditioning system utilizes and comprises a thermal evaporator tube within a standard condenser tube. The evaporator tube has a thermal refrigerant therein and is in communication with the thermal energy system utilizing a thermal compressor, such as a jet compressor or a thermally driven vapor compression cycle compressor. The thermal jet compressor is activated by high pressure motive vapor from a thermal boiler or flash tank and draws a lower pressure from a thermal evaporator. The thermal evaporator, which may have a tube-in-tube connection within the condenser, allows the fluid contained within the thermal evaporator to absorb heat from the condenser refrigerant fluid.
If the motive vapor and the thermal refrigerant fluid are the same, the cycle is completed as the fluid from the thermal jet compressor is condensed and recycled back to the boiler or flash tank. If the thermal refrigerant fluid and the motive fluid are not the same, they are separated in an accumulator tank before being recycled to their respective systems. At those times where there is insufficient thermal energy to drive the jet compressor, the refrigerant or air conditioning system operates as a normal fin tube condenser permitting latent heat to be given off through the walls of the condenser tube to the ambient atmosphere flowing therethrough.
In one embodiment of the present invention, the thermal energy is simply used to boil and hence vaporize a refrigerant contained in the boiler, which vaporized refrigerant flows through an appropriate shut-off valve into a jet compressor. Upon reaching a predetermined pressure to open the shut-off valve, the vaporized fluid flows through the jet compressor to draw a lower pressure on the discharge side of the compressor. The output from the compressor then flows through the jet compressor and into the condenser. From the condenser, a portion of the condensed fluid will flow through an expansion valve or any other suitable expansion means into an evaporator with another portion being returned through a condensate return pump to the boiler. The compressor again pressurizes the vapor by drawing a vacuum on the outlet of the evaporator. Basically, this provides a two-step compression system which can increase the overall efficiency of the system several times.